BOC BGA package for die with I-shaped bond pad layout

ABSTRACT

Semiconductor die units for forming BOC BGA packages, methods of encapsulating a semiconductor die unit, a mold for use in the method, and resulting encapsulated packages are provided. In particular, the invention provides a semiconductor die unit comprising an integrated circuit die with a plurality of bond pads in an I-shaped layout and an overlying support substrate having an I-shaped wire bond slot.

FIELD OF THE INVENTION

[0001] The present invention relates generally to packaging electroniccomponents, and particularly to methods of encapsulating board-on-chip(BOC) ball grid array (BOA) integrated circuit die units, andparticularly to die units with non-standard bond pad layouts includingan I-shaped bond pad layout.

BACKGROUND OF THE INVENTION

[0002] Integrated circuit (IC) chips are enclosed in plastic packagesthat provide protecting against damage and environmental contaminants,and enable electrical of the chip to other circuits on a printed circuitboard. Packaging IC chips has involved the placement of a chip on aflexible board where following adhesion of the chip to the board andwire bonding to connect the leads from the chip to the terminals on theboard, an encapsulant is flowed over the chip and board to form a sealedpackage.

[0003] Plastic encapsulation of semiconductor devices by transfermolding is a conventionally used technique. Typically, apre-encapsulated die unit is placed in a mold having top and bottomcavity molding plates. The lower molding plate has a constricted channelor mold gate along one side of the plate, and the encapsulationmaterial, typically a thermoplastic or thermosetting material, entersthrough the mold gate and flows under and then over the IC chip to coverthe electrical leads. The mold gate limits the flow rate and injectionvelocity of a molding compound into the cavity. The encapsulationmaterial is then cured to harden it. In devices having a ball grid array(BOA) on one side of the substrate, the molding process is conducted sothat the ball grid array connections are not covered by the moldingcompound during the encapsulation process.

[0004] The assembly process flows of standard BOC BOA packagingtechniques are set-up for conventional IC chips having a bond pad layoutarranged in a column down the center of the chip. Such packagingtechniques cannot accommodate the assembly of die packages that do notutilize a standard wire bond slot and bond pad layout.

[0005] Currently, a semiconductor chip having a non-standard bond padlayout is packaged in a chip-on-board (COB) ball grid array (BGA)package. A disadvantage in using a COB BGA packaging technique is theuse of long wires for connecting the bond pads in the center of the dieto contacts on the underlying substrate, which are prone to damage.Another drawback is the resulting larger package size, which is neededto allow sufficient space for the wire bond connections.

[0006] In view of these and other deficiencies in conventional methodsfor fabricating BGA packages, improvements in fabrication methods forBOC BGA packages are needed.

SUMMARY OF THE INVENTION

[0007] The present invention provides semiconductor assemblies forforming BOC BGA packages, methods of encapsulating a semiconductor dieunit, a mold assembly for use in the method, and resulting encapsulateddie packages. In particular, the invention provides a semiconductor dieunit comprising an integrated circuit die with a plurality of bond padsin an I-shaped layout and an overlying support substrate having anI-shaped wire bond slot.

[0008] In one aspect, the invention provides a method of encapsulatingan integrated circuit die unit. In one embodiment, the method comprisesproviding a mold containing a die unit; the mold having first and secondmolding plates, a molding chamber, and a mold gate through the firstmolding plate providing a conduit for flowing a molding compound intothe chamber, the mold gate oriented perpendicular to the second moldingplate; the die unit comprising a die mounted onto a support substrate,the die having a first surface, a second surface, and sides, the firstsurface of the die comprising a plurality of bond pads formed thereon,and mounted onto the support substrate with the bond pads exposedthrough an opening of the support substrate; the die unit positionedwithin the mold such that the mold gate is oriented perpendicular to theopening in the support substrate of the die unit; and introducing amolding compound through the mold gate to flow the molding compound intothe opening in the support substrate of the die unit to enclose the bondpads on the die.

[0009] In another embodiment, the method comprises providing a moldhaving a molding chamber and a mold gate providing a conduit forintroducing a molding compound into the chamber; providing a die unitcomprising a die having a first (active) surface, a second (inactive)surface, and sides, with the first surface of the die having electricalelements and a plurality of bond pads disposed thereon, the die mountedonto a support substrate with the bond pads exposed through an openingof the support substrate; placing the die unit in the mold with the moldgate oriented perpendicular to the first surface of the die; andintroducing a molding compound through the mold gate whereby the moldingcompound flows into the opening in the support substrate to enclose theelectrical elements and bond pads on the die.

[0010] In another embodiment of the method, the molding compound can beflowed onto the sides of the die and, optionally, onto the second(inactive) surface of the die, for example, through a gap or hole in thesubstrate of the die unit. In another embodiment of the method, themolding compound can be delivered through the mold gate onto a die unitat various positions along the wire bond slot, for example, at or nearone end of the wire bond slot to about the center of the slot, and thecompound flowed to fill the opening. In other embodiments of the method,the molding compound can be delivered into the mold chamber and into thewire bond slot opening in a downward or in an upward direction, forexample, by orienting the mold gate and die unit relative to each otherto achieve the desired upward or downward flow. In yet anotherembodiment, the method can be used for encapsulating a BOC BGA die unithaving a wire bond slot and a plurality of bond pads in an I-shapedconfiguration or other non-standard layout.

[0011] In another embodiment, the method comprises the steps of:providing a die comprising a first surface, a second surface, andopposing sides, the first surface having electrical elements and aplurality of bond pads disposed thereon in an I-shaped layout; mountingthe die onto a support substrate with the bond pads exposed through anI-shaped wire bond slot of the support substrate; electricallyconnecting the bond pads through the opening to bond pad fingers mountedon the support substrate adjacent to the opening to form apre-encapsulated die unit; providing a mold having a molding chamber anda mold gate providing a conduit for introducing a molding compound intothe chamber; placing the die unit in the mold with the mold gateoriented perpendicular to the opening of the support substrate of thedie unit; and introducing a molding compound through the mold gate toflow the molding compound into the opening of the support substrate toenclose the electrical elements and bond pads on the first surface ofthe die. In another embodiment, the die is mounted onto the supportsubstrate to provide a gap between a peripheral edge of the die and theopening of the support substrate; and in the step of introducing themolding compound, the molding compound flows through the gap and onto atleast the sides of the die. In yet another embodiment, the supportsubstrate includes holes therethrough adjacent to the gaps, and the dieis mounted onto the support substrate such that the holes through thesupport substrate are uncovered, and the molding compound is flowedthrough the gap and the holes in the substrate to cover at least thesides of the die.

[0012] In another aspect, the invention provides a mold forencapsulating a semiconductor die. In one embodiment, the mold comprisesfirst and second molding plates, a chamber, and a mold gate providing aconduit for introducing a molding compound into the chamber, with themold gate oriented in a first molding plate to deliver a moldingcompound into the chamber perpendicularly into a wire bond slot of a dieunit positioned between the two plates of the mold. The mold gate in thefirst molding plate is oriented perpendicular to the second moldingplate, and perpendicular to the wire bond slot of the support substrateof the die unit positioned in the mold. The mold gate can positioned asdesired within a molding plate to deliver the molding compound onto adie unit at or near one end of the wire bond slot to about the center ofthe slot, and the molding compound flowed to fill the opening. The moldgate and die unit can also be oriented to deliver the molding compoundinto the mold chamber in a downward or an upward direction into the wirebond slot opening. The mold can be structured to inhibit or allowflowing of the molding compound onto the sides and, optionally, thesecond (inactive), surface of the die.

[0013] In another aspect, the invention provides a semiconductorassembly. In one embodiment, the assembly comprises a board-on-chip(BOC) ball grid array (BGA) die unit having a die with a plurality ofbond pads in an I-shaped layout exposed through an I-shaped wire bondslot of an overlying support substrate. The die unit can further includean adhesive layer interposed between the die and the support substrate,for example, an adhesive sheet having an I-shaped opening correspondingto the opening of the support substrate, or a pair of adhesive stripspositioned on opposite sides and adjacent to the I-shaped opening.

[0014] In another embodiment, the die unit can include a feature such asa gap or a hole through which a molding compound can flow onto the sidesof the die and, optionally, onto the inactive surface of the die, whenthe die unit is placed into a mold for encapsulation. In one example,the support substrate (and die) can be dimensioned (and configured) suchthat mounting the die onto the support substrate provides a gap betweena peripheral edge of the die and the wire bond slot of the supportsubstrate. In another example, a hole can be provided adjacent the wirebond slot to provide an opening through the support substrate. The dieunit can be partially encapsulated with only the active surface of thedie and, optionally, the sides of the die encapsulated with a moldingcompound, and the inactive surface of the die exposed. The die unit canalso be completely overmolded by a molding compound.

[0015] The invention advantageously provides a BOC BGA package for ICdies and chips having an I-shaped bond pad configuration or othernon-standard layout, and an assembly process to build such a package.The present BOC BGA semiconductor package is easier to assembly than COBBGA packages, particularly in terms of wire bonding and moldingprocesses, and achieves a smaller package size with improved electricalperformance due to shorter wire lengths. In addition, the BOC BGApackaging maintains a conventional solder ball grid array to facilitateits use in conventional semiconductor assemblies. The present inventioncan be applied to both single-in-line strip (SIS) BOC configurations inwhich the arrangement of units within the strip is limited to a singlerow, and matrix BOC configurations in which the strip configuration isin an array form and the arrangement of units is not limited to a singlerow.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Preferred embodiments of the invention are described below withreference to the following accompanying drawings, which are forillustrative purposes only. Throughout the following views, thereference numerals will be used in the drawings, and the same referencenumerals will be used throughout the several views and in thedescription to indicate same or like parts.

[0017]FIG. 1A is a top plan view of an embodiment of an integratedcircuit die having bond pads in an I-shaped layout for fabricating anencapsulated board on chip (BOC) die unit according to an embodiment ofa method of the invention. FIG. 1B is a side elevational view of theintegrated circuit die of FIG. 1A taken along line 1B-1B.

[0018]FIG. 2A is top plan view of an embodiment of a support substratehaving an I-shaped opening for use with the integrated circuit die ofFIG 1A. FIG. 2B is a side elevational view of the support substrate ofFIG. 2A taken along line 2B-2B, showing an adhesive layer attached tothe underside of the substrate.

[0019]FIG. 3A is a top plan view of a partially assembled die unitformed by mounting the integrated circuit die of FIG. IA onto theunderside of the support substrate of FIG. 2A.

[0020]FIG. 3B is a side elevational view of the die unit of FIG. 3A,taken along line 3B-3B. FIG. 3C is a bottom plan view of the die unit ofFIG. 3A.

[0021]FIG. 4 is a top plan view of an embodiment of an adhesive layerfor mounting the integrated circuit die of FIG. 1A onto the supportsubstrate of FIG. 2A, the adhesive layer having an I-shaped opening.

[0022]FIG. 5 is a bottom plan view of the support substrate of FIG. 2Awith another embodiment of an adhesive layer in the form of adhesivestrips for mounting the die of FIG. 1A onto the underside of the supportsubstrate.

[0023]FIG. 6A is a top plan view of the die unit of FIG. 3A encapsulated(top molded) according to a method of the invention to form a package.FIG. 6B is a side elevational view of the encapsulated package of FIG.6A, taken along line 6B-6B.

[0024]FIG. 7A is a top plan view of the encapsulated package of FIG. 6A,showing solder balls mounted thereon. FIG. 7B is a side elevational viewof the encapsulated package of FIG. 7A, taken along line 7B-7B.

[0025]FIG. 8A is a top plan view of another embodiment of a die unithaving a gap along the edge of the integrated circuit die and the wirebond slot of the support substrate. FIGS. 8B is a side elevational viewof the die unit of FIG. 8A, taken along line 8B-8B. FIG. 8C is a bottomplan view of the die unit of FIG. 8A.

[0026]FIG. 9A is a top plan view of the die unit of FIG. 8A encapsulated(top molded) according to a method of the invention to form a diepackage. FIG. 9B is a side elevational view of an embodiment of theencapsulated package of FIG. 9A taken along line 9B,B′-9B,B′, andshowing the die being fully overmolded. FIG. 9B′ is a side elevationalview of another embodiment of the encapsulated die package of FIG. 9A,also taken along line 9B,B′-9B,B′, and showing the sides of the diebeing overmolded and the second surface of the die exposed. FIG. 9C is abottom plan view of the encapsulated package shown in FIGS. 9A-9B. FIG.9D is a bottom plan view of the encapsulated package depicted in FIGS.9A-9B′.

[0027]FIG. 10A is a top plan view of the encapsulated die package ofFIG. 9A showing solder balls mounted thereon. FIG. 10B is a sideelevational view of the die package of FIGS. 10A, taken along line10B-10B.

[0028]FIG. 11A is a top plan view of another embodiment of a die unithaving a gap along the edge of the integrated circuit die and the wirebond slot of the support substrate, and openings through the supportsubstrate. FIGS. 11B is a side elevational view of the die unit of FIG.11A, taken along line 11B-11B. FIG. 11C is a bottom plan view of the dieunit of FIG. 11A.

[0029]FIG. 12A is a top plan view of the die unit of FIG. 11Aencapsulated according to a method of the invention. FIG. 12B is a sideelevational view of an embodiment of the encapsulated die package ofFIG. 12A, taken along line 12B,B′-12B,B′, and showing encapsulated sidesand an exposed second surface of the die. FIG. 12B′ is a sideelevational view of another embodiment of the encapsulated package ofFIG. 12A, also taken along line 12B,B′-12B, B′, showing the sides andsecond surface of the die being overmolded.

[0030]FIG. 13A is a top plan view of the encapsulated die package ofFIG. 12A showing solder balls mounted thereon. FIGS. 13B, 13B′ are sideelevational views of the encapsulated package of FIG. 13A, taken alongline 13B,B′-13B,B′, and corresponding to FIGS. 12B, 12B′, respectively.

[0031] FIGS. 14A-E are sequential processing steps of an embodiment of amethod of the invention for top gate molding the die unit shown in FIGS.8A-8C. FIG. 14A is a top plan view of a panel or strip of mold units forfabricating multiple die packages, each mold unit having a top moldgate. FIG. 14B is a side elevational view of a mold unit of FIG. 14Ataken along line 14B-14B, showing a die unit within a mold having a topmold gate oriented for downward delivery of a molding compound onto thedie unit and flow of the molding compound around the die. FIG. 14C is atop plan view of the die unit of FIG. 14B with the upper molding plateremoved, showing direction of flow of the molding compound. FIG. 14D isview of the resulting encapsulated die package within the mold. FIG. 14Eis a top plan view of the encapsulated die package.

[0032]FIG. 15A is a top plan view of another embodiment of a die unithaving an elongate opening (wire bond slot). FIGS. 15B-15C aresequential processing steps for encapsulating the die unit of FIG. 15Aaccording to an embodiment of a method of the invention utilizing themold depicted in FIG. 14A.

[0033] FIGS. 16A-C are sequential processing steps of another embodimentof a method of the invention for top gate molding a die unit accordingto the invention. FIG. 16A is a side elevational view of the die unitwithin another embodiment of a mold having a top mold gate oriented fordownward delivery of a molding compound onto the die unit and positionedat an end of a molding plate, showing flow of the molding compoundaround the die. FIG. 16B is a top plan view of the die unit of FIGS.8A-8C within the mold of FIG. 16A, with the upper molding plate removed,showing direction of flow of the molding compound. FIG. 16B′ is a topplan view of the die unit of FIG. 15A within the mold of FIG. 16A, withthe upper molding plate removed and showing direction of flow of themolding compound. FIG. 16C is a view of the mold and encapsulated dieunit. FIGS. 16D, 16D′ are top plan views of the encapsulated die unit ofFIG. 16C corresponding to FIGS. 16B, 16B′, respectively.

[0034]FIG. 17A is a side elevational view of another embodiment of amold having a mold gate positioned for upward delivery of the moldingcompound onto the die unit, and the direction of flow of the compound.FIG. 17B depicts the encapsulated die package.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] The invention will be described generally with reference to thedrawings for the purpose of illustrating the present preferredembodiments only and not for purposes of limiting the same. The figuresillustrate processing steps for use in packaging semiconductor devicesin accordance with the present invention. It should be readily apparentthat the processing steps are only a portion of the entire fabricationprocess.

[0036] As used herein, the terms “top” and “bottom”, “upper” and“lower”, “side” and “end” are used for illustrative purposes only, andare not meant to limit the description of the invention in any way.

[0037] An embodiment of an encapsulated integrated circuit die packageand method of fabricating the package according to the invention isdescribed with reference to FIGS. 1-7, illustrating one-sideencapsulation of the die.

[0038] As shown in FIGS. 1A-1B, an integrated circuit (semiconductor)die 10 is provided having a first (active) surface 12, a second(inactive) surface 14, and sides 16, 18. The first (active) surface 12of the die 10 has electrical elements (circuitry) and a plurality ofbond pads 20 formed thereon. In the illustrated example, the bond pads20 are formed on the die 10 in an I-shaped layout. The first (active)surface 12 of the die is mounted onto a support substrate 24 such thatthe bond pads 20 are exposed through an opening (wire bond slot) 30 inthe support substrate.

[0039] Referring to FIGS. 2A-2B, a support substrate 24 is providedhaving a first (upper) side 26, a second (under) side 28, and a wirebond slot or opening 30 that corresponds to the bond pad layout on thedie 10. The support substrate 24 typically comprises an electricallyinsulating material such as an organic polymer resin reinforced withglass fibers. An exemplary BGA support substrate comprises a reinforcedpolymer laminate material such as bismaleimide triazine (BT) resins, ora polyimide resin. A typical thickness of the support substrate is about0.2 mm to about 1.6 mm.

[0040] In the illustrated example, the support substrate 24 includes anI-shaped wire bond slot or opening 30 that corresponds to the bond padlayout on the die 10, through which wire bonding connects the bond pads20 with contacts 32 on the upper side 26 of the support substrate 24.The I-shaped wire bond slot 30 has a main elongate segment 34 and a pairof shorter elongate segments 36 that are perpendicular to and onopposing ends 38 of the main elongate segment 34.

[0041] A plurality or series of bond pad fingers (contacts) 32 areformed on the first (upper) side 26 of the support substrate 24 adjacentto the edge or periphery 40 of the wire bond slot 30. The bond padfingers 32 comprise a conductive metal such as copper, aluminum, amongothers. A plurality of ball pads 42 comprising a conductive metal layerand shown in a series of two parallel rows, are formed on the first(upper) side 26 of the support substrate 24 adjacent to the bond padfingers 32. The bond pad fingers are electrically connected to the ballpads 42 by traces (not shown) within the support substrate 24.

[0042] As shown in FIGS. 3A-3B, the first (active) surface 12 of the die10 is mounted against the underside 28 of the support substrate 24, withthe bond pads 20 exposed through the wire bond slot 30 in the supportsubstrate 24. Any conventional affixation technique can be used. Forexample, the die 10 can be secured to the support substrate 24 with anadhesive such as epoxy, an adhesive tape, or other available technique.In a preferred example, a layer of adhesive tape 44 is interposedbetween the support substrate 24 and the die 10.

[0043] As shown in FIG. 4, in one embodiment, the adhesive layer 44 cancomprise an adhesive sheet 46 having an I-shaped opening 48 thatcorresponds to the I-shaped wire bond slot 30 of the support substrate24, and can be attached to the underside 28 of the support structure 24.In another ′embodiment as shown in FIG. 5, the adhesive layer 44 cancomprise a pair of adhesive strips 50 that are positioned along oppositesides and adjacent to the I-shaped wire bond slot 30 on the underside 28of the support substrate 24. The adhesive layer 44 is applied to theunderside 28 of the support structure along the edge of the opening 30.

[0044] As further shown in FIGS. 3A-3B, bond wires 52 are connected fromthe bond pads 20 on the die 10 through the wire bond slot 30 to the bondpad fingers 32 on the first (upper) side 26 of the support substrate 24,resulting in a die-mounted and wire-bonded unit (“die unit”) 54. Theconfiguration of the illustrated die unit 54 is known as a board-on-chip(BOC), in which the integrated circuit die or chip 10 is attached to thesecond (under) side 28 of a support substrate 24.

[0045] Referring now to FIGS. 6A-6B, the BOC die unit 54 can beencapsulated with a molding compound 56 to pot the bond wires 52 and thebond pad fingers 32, and fill the wire bond slot 30 of the supportsubstrate 24 to encapsulate the electronic components and the bond pads(20) on the first (active) surface 12 of the die 10, resulting in anencapsulated package 58. As depicted, the second (inactive) surface 12of the die is exposed. The molding compound 56 is dried, set or cured toa solid phase. The molding compound is preferably a thermoset epoxyresin, for example, a novolac epoxy resin-based compound, that producesa rigid plastic body surrounding the die.

[0046] Following the encapsulation, solder balls 60 can beconventionally bonded to the ball pads 42, as depicted in FIGS. 7A-7B. Asolder reflow process can be used to bond the solder balls to the ballbond pads. The solder balls provide external electrical connections tothe die, and permit the package to be surface mounted to a printedcircuit board (PCB) or other electronic component.

[0047] Optionally, a heat sink (dissipater), for example, an extrudedaluminum plate, a solder dam or ring, and other known devices (notshown), can be attached onto the die 10 to absorb and dissipate heatgenerated by electronic components. Heat sinks are known and used in theart, as described, for example, in U.S. Pat. No. 6,122,171 (Akram etal.).

[0048] In the foregoing embodiment, the molding compound 54 is disposedpartially upon the support substrate 24 and partially upon the first(active) surface 12 of the die 10, with the second (inactive) surface 14and sides 16, 18 of the die 10 exposed and not covered by the moldingcompound.

[0049] Another embodiment of an encapsulated die package 58′ and methodof the invention is illustrated in FIGS. 8-10. The die unit 54′ isstructured to allow the molding compound to flow onto the sides, and, ifdesirable, the second (inactive) surface of the die to encapsulate thesides and the second surface of the die.

[0050] Referring to FIGS. 8A-8C, the support substrate 24′ isdimensioned such that mounting the first (active) surface 12′ of the dieonto the underside 28′ of the support substrate 24′ provides a gap 62′between a peripheral edge 64′ along side 16′ of the die 10′ and the wirebond slot 30′ of the support substrate 24′. As shown, the gaps 62′ areformed along opposing edges 64′ along sides 16′ of the die 10 and outeredges 66′ of the shorter elongate segments 36′ of the wire bond slot30′. The bond pads 20′ on the die 10′ are then wire bonded to the bondpad fingers 32′ on the support substrate 24′, resulting in the die unit54′.

[0051] As depicted in FIGS. 9A-9B, the die unit 54′ can be encapsulatedwith a molding compound 56′ to cover the bond wires 52′, bond padfingers 32′, and wire bond slot 30′ including electronic components andthe bond pads 20′ on the first (active) surface 12′ of the die 10′. Inthe encapsulation step, the molding compound 56′ is flowed through thegap 62′ and onto the sides 16′, 18′, of the die 10′. The mold (notshown) into which the die unit 54′ is placed for the encapsulation step,is structured and sized to provide sufficient clearance (i.e., an openspace) along the sides 16′, 18′ of the die 10′ into which the moldingcompound 56′ can flow to encapsulate the sides.

[0052] Where it is desirable to encapsulate the second (inactive)surface 14′ of the die 10, the mold (not shown) is structured to providesufficient clearance along the second (inactive) surface 14′ of the dieto, allow the molding compound 56′ to flow over and encapsulate thesecond surface of the die, resulting in the die package 58′ shown inFIGS. 9B-9C. The mold (not shown) can also be structured to prevent themolding compound 56′ from flowing further onto the second (inactive)surface 14′ of the die 10′, such that the second (inactive) side of thedie is exposed and not covered by the molding compound, resulting in thedie package 58(1)′ as depicted in FIGS. 9B′, 9D. This embodiment 58(1)′of the die package provides a package having a reduced height(thickness), resulting in a thinner package overall.

[0053] Following the encapsulation, solder balls 60′ can be bonded tothe ball pads 42′ on the first (upper) surface 26′ of the supportstructure 24′, as depicted in FIGS. 10A-10B.

[0054] Yet another embodiment of a die package 58″ and method accordingto invention is illustrated in FIGS. 11-13. The die unit 54″ is againstructured to allow the molding compound to flow onto and encapsulatethe sides and, optionally, the second (inactive) surface of the die.

[0055] As shown in FIGS. 11A-11C, the support substrate 24″ is providedwith holes 68″ therethrough, which are positioned adjacent to theopposing ends 70″ of the shorter elongate segments 36″ of the I-shapedwire bond slot 30″. The die 10″ and the support substrate 24′ aredimensioned and configured such that mounting the first (active) surface12″ of the die 10″ onto the underside 28″ of the support substrate 24″forms a gap 72″ between a peripheral edge 74″ along the side 18″ of thedie 10″ and the opposing ends 70″ of the shorter elongate segments 36″of the wire bond slot 30″, and also leaves the holes 68″ through thesupport substrate 24 uncovered. The bond pads 20″ on the die 10″ arethen wire bonded to the bond pad fingers 32″ on the support substrate24″, resulting in the die unit 54″.

[0056] In encapsulating the die unit 54″, the molding compound 56″ isflowed over the bonding wires 52″ and bond pad fingers 32″ and to fillthe I-shaped wire bond slot 30″, as depicted in FIG. 12A. The moldingcompound 56″ is further flowed through the gaps 72″ and the holes 68″ inthe substrate 24″ onto the sides 16″, 18″ of the die 10″, as depicted inFIG. 12B, resulting in the die package 58″. Optionally, the moldingcompound 56″ can be flowed onto the second (inactive) surface 14″ of thedie 10″ as depicted in FIGS. 12B′, resulting in the die package 58(1)″.

[0057] Solder balls 60″ can then be bonded to the ball pads 42″ on theupper surface 26″ of the support structure 24″, as depicted in FIG. 13Aand in cross-sectional view in FIGS. 13B, 13B′, corresponding to theembodiments depicted in FIGS. 12B, 12B′, respectively.

[0058] It is understood that in the embodiment of the die unit 54″illustrated in FIGS. 11-13, that the die unit 54″ can be structured witheither or both of the described hole(s) 68″ or gap(s) 72″.

[0059] The invention can be applied to encapsulate one or both surfaces(and sides) of an IC die. Referring now to FIGS. 14A-14E, an embodimentof a mold 74 and method of encapsulating an integrated circuit die unitaccording to the invention will be described with reference to the dieunit 54′ depicted in FIGS. 8A-8C, which includes gaps 62′ along theedges 64′ of the integrated circuit die 10′ and segment 36′ of the wirebond slot 30′. As shown in FIG. 14A, the mold 74 can be initially asegment (A) of a panel or strip 75 to fabricate multiple die packages.Following the fabrication process for the packages, the panel 75 issingulated into individual BGA packages. As depicted in FIG. 14B, themold 74 includes first and second plate members (mold halves) 76, 78,that define a chamber 80, the first plate member 76 having a top moldgate (pin cavity) 82 to provide a conduit for introducing a moldingcompound 56′ into the chamber 80. It is understood that the describedmold and method can be utilized for one-side encapsulation of an IC dieas depicted with reference to FIGS. 1-7.

[0060] In the illustrated example to encapsulate a die unit having a gap(and/or a hole), the mold 74 is sized and structured to providesufficient clearance (i.e., an open space 84, 86) along the sides 16′,18′ and, if desired, along the second (inactive) surface 14′ of the die10′, into which the molding compound 56′ can flow to encapsulate thesides and second surface of the die. If it is desired that the secondsurface 14′ of the die 10′ remain exposed, the mold 74 can be structuredto eliminate the open space 86 adjacent the second surface 14′ of thedie 10′.

[0061] According to the invention, the molding plates have been modifiedfrom a conventional configuration such that the mold gate 82 is formedin one of the first or second plate members 76, 78, and is orientedperpendicular to the upper side 28′ of the support substrate 24′ and thefirst (active) surface 12′ of the die 10′ of the die unit 54′ positionedin the mold 74. As such, the molding compound 56′ passes through themold gate 82 in the direction of arrow 88, and flows directly onto theupper side 28′ of the substrate and into the wire bond slot 30′. Themolding compound 56 is flowed through the mold gate 82 under pressure,typically at about 500 psi to about 2,000 psi.

[0062] In the embodiment depicted in FIGS. 14B-14C, the mold gate 82 islocated in the first plate member 76 (and oriented perpendicular to thesecond plate member 78) to dispense the molding compound 56′ in adownward direction (arrow 88) onto the die unit 54′ at about the centerof the main elongate segment 34′ of the I-shaped wire bond slot 30′ ofthe support substrate 24′. The molding compound 56′ is then flowed overthe support substrate 24′ and active surface 12′ of the die 1O′ alongthe main elongate segment 34′ in the direction of the arrows 90 to theshorter elongate segments 36′ of the wire bond slot 30′. The moldingcompound 56′ is then flowed through the gap 62′ (arrow 92) and into theopen spaces 84, 86 to cover the sides 16′, 18′ and the second surface14′ of the die 10′. The resulting encapsulated package 58′ is depictedin FIGS. 14D-14E.

[0063] The method and mold described with reference to FIGS. 14A-14E canalso be used to similarly encapsulate a die unit 54′″ in which the wirebond slot in the support substrate is a different configuration such asan elongate opening 30′″, as depicted in FIG. 15A. Optionally, as shown,the die unit 54′″ can include a gap 62′″ and/or hole 68′″ for passage ofthe molding compound 56′″ onto the sides 16′″, 18′″, and the second(inactive) surface 14′″ of the die 10′″. In the use of the mold 74described in connection with FIGS. 14A-E, the molding compound 56′″ canbe flowed onto about the center 92′″ of the elongate opening 30′″ and toeither end in the direction of arrows 90′″, as shown in FIG. 15B. Themolding compound 56′″ can then be flowed through the gap 62′″ and/orhole 68′″ onto the sides (16′″, 18′″) of the die, and optionally ontothe second surface (14′″) of the die 10′″ as desired (see FIG. 14B),resulting in the encapsulated package 58′″ depicted in FIG. 15C (and incross-section in FIG. 14D).

[0064] The location, size and shape of the top (or bottom) mold gate(pin cavity) is not restricted, and can be designed to achieve theoptimal flow of the molding compound for different die and packagesizes. It is understood that the mold gate can be located in the firstor second plate members to dispense the molding compound directly ontothe upper surface of the support substrate and the first (active)surface of the die of the die unit at any point along the wire bond slotof the support substrate.

[0065] Another embodiment of a mold 74′, is illustrated in FIGS.16A-16B. As shown, the mold gate 82′ is located at one end of the firstplate member 76′ to dispense the molding compound 56′ in a downwarddirection at or near a first end 30′ of the main elongate segment 34′ ofthe I-shaped wire bond slot 30′ in the support substrate 24′. Themolding compound 56′ is introduced through the mold gate 82′ in thedirection of arrow 88′ onto the substrate 24′ and into the wire bondslot 30′. The molding compound 56′ is flowed in the direction of arrows90′ to the shorter elongate segments 36′ of the wire bond slot 30′, andthrough the gap 62′ (and/or holes) in the direction of arrows 92′. Asdepicted, the molding compound 56′ is flowed onto the sides 16′ of thedie 10′ and (optionally) the second surface 14′ of the die 10′,resulting in a die package 58′, such as depicted in FIGS. 14D-14E.

[0066] In another embodiment, the mold 74, 74′ can be used toencapsulate a die unit having a different shaped wire bond slot in thesubstrate and bond pad layout, for example, the die unit 54′″ having anelongate slot (opening) 30′″ and pad layout, as shown in FIG. 15A. Insuch case, the molding compound 56′″ can be flowed onto an end 38 a′″ ofthe elongate opening 30′″ (FIGS. 16A, 16B′) and in the direction of thearrows 90′ to the other end 38 b′″ of the opening, and through the gap62′″ and/or hole 68′″ to encapsulate the sides 16′″, 18′″, and secondsurface 14′″ of the die 10′″.

[0067] With the foregoing mold assemblies and methods, the mold gate 82,82′ is shown as being oriented with respect to the die unit to allow themolding compound to be introduced through the mold gate in a downwardlydirection (arrow 88, 88′) directly onto the first (active) surface ofthe die. In some applications, the downward flow of the molding compoundcan apply an amount of pressure onto the die unit that causes thesupport substrate and die to bend. To avoid such an effect, in anotherembodiment of a mold 74″ and method illustrated in FIGS. 17A-17B, themold gate 82″ is oriented with respect to the die unit 54′ such that themolding compound 56″ is delivered through the mold gate 82″ in an upwarddirection (arrows 96″) onto the upper surface 28′ of the supportsubstrate 24′ and into the wire bond slot (30′), and can be furtherflowed through a gap 62′ and/or hole 68′ in the direction of arrows 92″onto the sides 16′, 18′, and the second (inactive) surface 14′ of thedie 10′, resulting in the encapsulated package 58′ shown in FIG. 17B.The advantage of orienting the die over the substrate during the moldingprocess and flowing the molding compound 56″ in an upward direction ontothe die unit provides an additional weight or force to present thesubstrate from bowing or bending. The mold gate 82″ can be located inthe second plate member 78′ (as shown), or in the first plate member(76) as illustrated in FIG. 14D whereby the mold (74) can be flipped sothat the molding compound can be flowed in a vertical direction (arrow96″) as depicted in FIG. 17A.

[0068] Either a conventional (side) mold gate molding process or thepresent top gate molding process can be utilized to encapsulate the BOCBGA die unit. Current molding methods of BOC devices utilize a moldhaving a mold gate along a side (perimeter) of the lower plate andpositioned adjacent to the die edge. As such, the encapsulant materialis dispensed horizontally into a side of the mold and flows under andover the support substrate onto the active surface of the die to coverthe wire bonds. In the described top gate molding process, the moldingcompound enters the mold through a mold gate positioned in the surfaceof the first (or second) molding plate, perpendicular to the othermolding plate and the surface of the die unit in the mold.

[0069] In a conventional molding method, the side-positioned mold gatein the lower molding plate is lined with a gold-plated copper foil toprevent encapsulant material from adhering to the edges of thesubstrate. Advantageously, the top mold gate of the present moldapparatus does not require a gold surface area on the substrate, thusproviding a reduction in the substrate cost in the manufacture of BOCFBGA packages.

[0070] The present top gate molding process also optimizes mold yield(the number of acceptable molded packages), compared to conventional BOCmolding processes, by reducing the number of rejected or substandardpackages.

[0071] Other disadvantages of conventional molding techniques includethe need for a standard wire bond slot quality for die placement, theuse of a diversion dam to divert the flow of the molding compound withinthe mold cavity, and the lack of consistency in thickness (height) ofthe diversion dam, which are limited by a supplier's capability withslot fabrication and soldermask printing (copper plating) to form thediversion dam. Variations in thickness of the tape between the die andthe substrate, the quality of the wire bond slot, and the height of thediversion dam can result in gaps being formed along the diversion damthrough which molding compound can seep onto a surface of the die unit.Such seepage of the molding compound out of the flow of the moldingcompound through the mold cavity can lower mold yield. The use of thepresent top gate molding process advantageously eliminates the need fora diversion dam. Also, unlike current molding processes that requiredifferent diversion dam locations and heights to accommodate differenttape thicknesses, the use of the present top gate molding process can besuccessfully applied to die units over a wide range of tape thicknesses.Elimination of the diversion dam also reduces package sizeconfiguration. In addition, the top gate molding process requires fewerprocess steps for substrate fabrication, resulting in shorter substratedelivery lead time and lower substrate costs.

[0072] In compliance with the statute, the invention has been describedin language more or less specific as to structural and methodicalfeatures. It is to be understood, however, that the invention is notlimited to the specific features shown and described, since the meansherein disclosed comprise preferred forms of putting the invention intoeffect. The invention is, therefore, claimed in any of its forms ormodifications within the proper scope of the appended claimsappropriately interpreted in accordance with the doctrine ofequivalents.

What is claimed is:
 1. A method of forming an integrated circuit diepackage, comprising the steps of: providing a mold containing a dieunit; the mold having a molding chamber and a mold gate providing aconduit for introducing a molding compound into the chamber; the dieunit comprising a die having a first surface, a second surface, andsides; the first surface of the die comprising a plurality of bond padsdisposed thereon, and being mounted onto a support substrate with thebond pads exposed through an opening of the support substrate; the dieunit positioned within the mold such that the mold gate is orientedperpendicular to the opening in the support substrate of the die unit;and introducing a molding compound through the mold gate to flow themolding compound into the opening in the support substrate of the dieunit to enclose the bond pads on the die.
 2. The method of claim 1,wherein the introducing step comprising flowing the molding compound ina downward direction into the opening in the support substrate.
 3. Themethod of claim 1, wherein the introducing step comprising flowing themolding compound in an upward direction into the opening in the supportsubstrate.
 4. The method of claim 1, wherein the mold comprises firstand second molding plates, and the mold gate is positioned in the firstmolding plate such that the molding compound is flowed into one end ofthe opening of the support substrate, and from one end of the opening tothe other end.
 5. The method of claim 1, wherein the mold comprisesfirst and second molding plates, and the mold gate is positioned atabout the center of the first molding plate such that the moldingcompound is flowed onto about the center of the opening of the supportsubstrate and toward each end of the opening.
 6. The method of claim 1,wherein the die is mounted onto the support substrate to provide a gapbetween a peripheral edge of the die and the opening of the supportsubstrate, and in the step of introducing the molding compound, themolding compound is flowed through the gap and onto the sides of thedie.
 7. The method of claim 6, wherein in the step of introducing themolding compound, the molding compound is further flowed onto the secondsurface of the die.
 8. The method of claim 6, wherein the mold isstructured to allow flowing of the molding compound onto the secondsurface of the die.
 9. The method of claim 6, wherein the mold isstructured to prevent flowing of the molding compound onto the secondsurface of the die, and the second surface of the die is notencapsulated by the molding compound.
 10. The method of claim 1, whereinthe support substrate comprises a hole therethrough and the die ismounted onto the support substrate such that the hole through thesubstrate is uncovered; and in the step of introducing the moldingcompound, the molding compound is flowed through the hole in thesubstrate and onto the sides of the die.
 11. The method of claim 1,wherein the bond pads are in an I-shaped layout on the first surface ofthe die; and the opening of the support substrate is I-shapedcorresponding to the layout of the bond pads.
 12. A method of forming anintegrated circuit die package, comprising the steps of: providing amold containing a die unit; the mold having first and second moldingplates, a molding chamber, and a mold gate through the first moldingplate providing a conduit for flowing a molding compound into thechamber, the mold gate oriented perpendicular to the second moldingplate; the die unit comprising a die having a first surface, a secondsurface, and sides; the first surface of the die comprising a pluralityof bond pads disposed thereon, and being mounted onto a supportsubstrate with the bond pads exposed through an opening of the supportsubstrate; the die unit positioned within the mold such that the moldgate is oriented perpendicular to the opening in the support substrateof the die unit; and introducing a molding compound through the moldgate to flow the molding compound into the opening in the supportsubstrate of the die unit.
 13. A method of forming an integrated circuitdie package, comprising the steps of: providing a mold containing a dieunit; the mold having a molding chamber and a mold gate providing aconduit for introducing a molding compound into the chamber; the dieunit comprising a die having a first surface, a second surface, andsides; the first surface of the die comprising a plurality of bond padsdisposed thereon, and being mounted onto a support substrate with thebond pads exposed through an opening of the support substrate, and a gapprovided between a peripheral edge of the die and the opening of thesupport substrate; the die unit positioned within the mold such that themold gate is oriented perpendicular to the opening in the supportsubstrate of the die unit; and introducing a molding compound throughthe mold gate to flow the molding compound into the opening in thesupport substrate of the die unit to enclose the bond pads on the die.14. The method of claim 13, wherein the mold is structured to allowflowing of the molding compound onto the second surface of the die; andthe introducing step further comprises flowing the molding compoundthrough the gap and onto the second surface of the die.
 15. The methodof claim 13, wherein the mold is structured to prevent flowing of themolding compound onto the second surface of the die, whereby theintroducing step further comprises flowing the molding compound throughthe gap and onto the sides of the die, and the second surface of the dieis not covered with the molding compound.
 16. The method of claim 13,wherein the bond pads are in an I-shaped layout on the first surface ofthe die; and the opening of the support substrate is I-shapedcorresponding to the layout of the bond pads.
 17. The method of claim16, wherein the I-shaped opening of the support substrate comprises amain elongate segment and a pair of shorter elongate segments positionedperpendicular to and on opposing ends of the main segment, and the gapis provided between the die and an edge of at least one of the shorterelongate segments.
 18. The method of claim 13, wherein the supportsubstrate further comprises holes therethrough on opposite ends of andadjacent to the shorter elongate segments of the I-shaped opening; andthe die is mounted onto the support substrate such that the holesthrough the support substrate are uncovered; and in the step ofintroducing the molding compound, the molding compound is flowed throughthe gap and the holes in the substrate and onto the sides of the die.19. A method of forming an integrated circuit die package, comprisingthe steps of: providing a mold containing a die unit; the mold havingfirst and second molding plates, a molding chamber and a mold gateproviding a conduit for introducing a molding compound into the chamber;the die unit comprising a die having a first surface, a second surface,and sides; the first surface of the die comprising a plurality of bondpads disposed thereon, and being mounted onto a support substrate withthe bond pads exposed through an opening of the support substrate; thedie unit positioned within the mold and the mold gate positioned in thefirst molding plate such that the mold gate is oriented perpendicular tothe one end of the opening in the support substrate of the die unit; andintroducing a molding compound through the mold gate to flow the moldingcompound into the one end of the opening in the support substrate of thedie unit and from one end of the opening to the other end of the openingto enclose the bond pads on the die.
 20. A method of forming anintegrated circuit die package, comprising the steps of: providing amold containing a die unit; the mold having first and second moldingplates, a molding chamber and a mold gate providing a conduit forintroducing a molding compound into the chamber; the die unit comprisinga die having a first surface, a second surface, and sides; the firstsurface of the die comprising a plurality of bond pads disposed thereon,and being mounted onto a support substrate with the bond pads exposedthrough an opening of the support substrate; the die unit positionedwithin the mold and the mold gate positioned in the first molding platesuch that the mold gate is oriented perpendicular to about the center ofthe opening in the support substrate of the die unit; and introducing amolding compound through the mold gate to flow the molding compound intoabout the center of the opening in the support substrate of the die unitand toward each end of the opening to enclose the bond pads on the die.21. A method of forming an integrated circuit die package, comprisingthe steps of: providing a mold containing a die unit; the mold having amolding chamber and a mold gate providing a conduit for introducing amolding compound into the chamber; the die unit comprising a die and asupport substrate, the die having a first surface, a second surface, andsides, the first surface of the die comprising a plurality of bond padsdisposed thereon; the support substrate having a hole therethrough; andthe die being mounted onto the support substrate with the bond padsexposed through an opening of the support substrate and the hole throughthe substrate uncovered; the die unit positioned within the mold suchthat the mold gate is oriented perpendicular to the opening in thesupport substrate of the die unit; and introducing a molding compoundthrough the mold gate to flow the molding compound into the opening inthe support substrate of the die unit and through the hole in thesubstrate to enclose the bond pads and the sides of the die.
 22. Amethod of forming an integrated circuit die package, comprising thesteps of: providing a mold containing a die unit; the mold having amolding chamber and a mold gate providing a conduit for introducing amolding compound into the chamber; the die unit comprising a die havinga first surface, a second surface, and sides; the first surface of thedie comprising a plurality of bond pads disposed thereon in an I-shapedlayout, and being mounted onto a support substrate with the bond padsexposed through an I-shaped opening of the support substrate; the dieunit positioned within the mold such that the mold gate is orientedperpendicular to the opening in the support substrate of the die unit;and introducing a molding compound through the mold gate to flow themolding compound into the opening in the support substrate of the dieunit to enclose the bond pads on the die.
 23. A method for encapsulatingan integrated circuit die, comprising the steps of: providing a moldhaving a molding chamber and a mold gate providing a conduit forintroducing a molding compound into the chamber; providing a die unitcomprising a die having a first surface, a second surface, and sides,the first surface of the die having a plurality of bond pads disposedthereon, the first surface of the die mounted onto a support substratewith the bond pads exposed through an opening of the support substrate;placing the die unit in the mold with the mold gate orientedperpendicular to the first surface of the die; and introducing a moldingcompound through the mold gate whereby the molding compound flows intothe opening in the support substrate to enclose the bond pads on thedie.
 24. The method of claim 23, wherein the mold gate is positioned atone end of the opening of the support substrate, and the moldingcompound is flowed from one end of the opening to the, other end. 25.The method of claim 23, wherein the mold gate is positioned at about thecenter of the opening of the support substrate, and the molding compoundis flowed onto about the center of the opening and toward each end ofthe opening.
 26. A method for encapsulating an integrated circuit die,comprising the steps of: providing a mold having a molding chamber and amold gate providing a conduit for introducing a molding compound intothe chamber; providing a die unit comprising a die having a firstsurface, a second surface, and side surfaces; the first surface of thedie having a plurality of bond pads disposed thereon; the first surfaceof the die mounted onto a support substrate with the bond pads exposedthrough an opening of the support substrate, and a gap provided betweena peripheral edge of the die and the opening of the support substrate;placing the die unit in the mold with the mold gate orientedperpendicular to opening of the support substrate and the first surfaceof the die; and introducing a molding compound through the mold gate toflow the molding compound into the opening of the support substrate toenclose the bond pads on the die, and through the gap onto the sides ofthe die.
 27. The method of claim 26, wherein the introducing stepfurther comprising flowing the molding compound through the gap and ontothe second surface of the die.
 28. The method of claim 26, wherein themold is structured to allow flowing of the molding compound onto thesecond surface of the die.
 29. The method of claim 26, wherein the moldis structured to prevent flowing of the molding compound onto the secondsurface of the die, and the second surface of the die is not coveredwith the molding compound.
 30. The method of claim 26, wherein the bondpads are in an I-shaped layout on the first surface of the die; and theopening of the support substrate is I-shaped corresponding to the layoutof the bond pads.
 31. The method of claim 26, wherein the I-shapedopening of the support substrate comprises a main elongate segment and apair of shorter elongate segments positioned perpendicular to and onopposing ends of the main segment, and the gap is provided between thedie and an edge of at least one of the shorter elongate segments. 32.The method of claim 26, wherein the support substrate further comprisesholes therethrough on opposite ends of and adjacent to the shorterelongate segments of the I-shaped opening; and the die is mounted ontothe support substrate such that the holes through the support substrateare uncovered; and in the step of introducing the molding compound, themolding compound is flowed through the gap and the holes in thesubstrate and onto the sides of the die.
 33. A method for encapsulatingan integrated circuit die, comprising the steps of: providing a diecomprising a first surface, a second surface, and opposing sides; thefirst surface with electrical elements and a plurality of bond padsdisposed thereon, the bond pads in an I-shaped layout on the firstsurface; mounting the first surface of the die onto a support substratewith the bond pads exposed through an opening of the support substrate;the opening being I-shaped; electrically connecting the bond padsthrough the opening to bond pad fingers mounted on the support substrateadjacent to the opening to form a die unit; providing a mold having amolding chamber and a mold gate providing a conduit for introducing amolding compound into the chamber; placing the die unit in the mold withthe mold gate oriented perpendicular to the opening of the supportsubstrate of the die unit; and introducing a molding compound throughthe mold gate to flow the molding compound into the opening of thesupport substrate to enclose the electrical elements and bond pads onthe first surface of the die unit.
 34. The method of claim 33, whereinthe die is mounted onto the support substrate to provide a gap between aperipheral edge of the die and the opening of the support substrate; andin the step of introducing the molding compound, the molding compoundflows through the gap and onto at least the sides of the die.
 35. Themethod of claim 33, wherein the I-shaped opening of the supportsubstrate comprises a main elongate segment and a pair of shorterelongate segments positioned perpendicular to and on opposing ends ofthe main segment, and the gap is provided along a side of at least oneof the shorter elongate segments.
 36. The method of claim 33, whereinthe support substrate further comprises holes therethrough on oppositeends of and adjacent to the shorter elongate segments of the I-shapedopening; and the die is mounted onto the support substrate such that theholes through the support substrate are uncovered; and in the step ofintroducing the molding compound, the molding compound is flowed throughthe gap and the holes in the substrate and onto at least the sides ofthe die.
 37. The method of claim 34, wherein the mold is structured toallow flowing of the molding compound to enclose the second surface ofthe die.
 38. The method of claim 34, wherein the mold is structured toprevent flowing of the molding compound onto the second surface of thedie, and the second surface of the die is not covered with the moldingcompound.
 39. A method for encapsulating an integrated circuit die,comprising the steps of: providing a mold having a molding chamber and amold gate providing a conduit for introducing a molding compound intothe chamber; providing a die comprising a first surface and a secondsurface, the first surface with electrical elements and a plurality ofbond pads disposed thereon; providing a support substrate comprising anopening, a plurality of bond pad fingers disposed on a side of thesubstrate adjacent to the opening, and a plurality of ball pads disposedon the substrate adjacent to the bond pad fingers; mounting the die ontothe support substrate to align and expose the plurality of bond padsthrough the opening of the support substrate; electrically connectingthe bond pads through the opening to the bond pad fingers on the supportsubstrate to provide a die unit; providing a mold having a moldingchamber and a mold gate providing a conduit for introducing a moldingcompound into the chamber; placing the die unit in the mold with themold gate oriented perpendicular to the opening in the substrate and thefirst surface of the die; and introducing a molding compound through themold gate whereby the molding compound flows directly into the openingin the support substrate to enclose the bond pad fingers and theelectrical elements of the die.
 40. A method for encapsulating anintegrated circuit die, comprising the steps of: providing a mold havinga molding chamber and a mold gate providing a conduit for introducing amolding compound into the chamber; providing a die comprising a firstsurface, a second surface, and sides; the first surface with electricalelements and a plurality of bond pads disposed thereon; providing asupport substrate having an I-shaped opening comprising a main elongatesegment and a pair of shorter elongate segments positioned perpendicularto and on opposing ends of the main segment; a plurality of bond padfingers disposed on a side of the substrate adjacent to the opening, anda plurality of ball pads disposed on the substrate adjacent to the bondpad fingers; mounting the die onto the support substrate to align thebond pads within the I-shaped opening of the support substrate, andprovide a gap along a peripheral edge of the die and an edge of at leastone of the shorter elongate segments of the opening in the supportsubstrate; electrically connecting the bond pads through the opening tothe bond pad fingers on the support substrate; providing a mold having amolding chamber and a mold gate providing a conduit for introducing amolding compound into the chamber; placing the mounted die in the moldwith the mold gate oriented perpendicular to the opening in thesubstrate; and introducing a molding compound through the mold gate toflow the molding compound into the opening into the substrate to enclosethe bond pad fingers and the electrical elements of the die, and throughthe gap to enclose the sides of the die.
 41. A method for encapsulatingan integrated circuit die, comprising the steps of: providing a moldhaving a molding chamber and a mold gate providing a conduit forintroducing a molding compound into the chamber; providing a diecomprising a first surface, a second surface, and sides; the firstsurface with electrical elements and a plurality of bond pads disposedthereon; providing a support substrate having an I-shaped openingcomprising a main elongate segment and a pair of shorter elongatesegments positioned perpendicular to and on opposing ends of the mainsegment; a plurality of bond pad fingers disposed on a side of thesubstrate adjacent to the opening, and a plurality of ball pads disposedon the substrate adjacent to the bond pad fingers; mounting the die ontothe support substrate to align the bond pads within the I-shaped openingof the support substrate, and provide a gap along a peripheral edge ofthe die and an edge of at least one of the shorter elongate segments ofthe opening of the support substrate; electrically connecting the bondpads through the opening to the bond pad fingers on the supportsubstrate; providing a mold having a molding chamber and a mold gateproviding a conduit for introducing a molding compound into the chamber;placing the mounted die in the mold with the mold gate orientedperpendicular to the opening of the support substrate; and introducing amolding compound through the mold gate to flow the molding compound intothe opening of the substrate to enclose the bond pad fingers and theelectrical elements of the die, and through the gap to enclose the sidesof the die.
 42. A method for encapsulating an integrated circuit die,comprising the steps of: providing a mold having a molding chamber and amold gate providing a conduit for introducing a molding compound intothe chamber; providing a die comprising a first surface, a secondsurface, and sides; the first surface with electrical elements and aplurality of bond pads formed thereon; providing a support substratehaving an I-shaped opening comprising a main elongate segment and a pairof shorter elongate segments positioned perpendicular to and on opposingends of the main segment; a hole through the support substrate onopposite ends of and adjacent to the shorter elongate segments of theI-shaped opening; a plurality of bond pad fingers formed on a side ofthe substrate adjacent to the opening, and a plurality of ball padsformed on the substrate adjacent to the bond pad fingers; mounting thedie onto the support substrate to align the bond pads within theI-shaped opening of the support substrate such that the holes throughthe support substrate are uncovered; electrically connecting the bondpads through the opening to the bond pad fingers on the supportsubstrate; providing a mold having a molding chamber and a mold gateproviding a conduit for introducing a molding compound into the chamber;placing the mounted die in the mold with the mold gate orientedperpendicular to the opening in the support substrate; and introducing amolding compound through the mold gate to flow the molding compounddirectly into the opening of the substrate to enclose the bond padfingers and the electrical elements of the die, and through the hole inthe substrate onto the sides of the die.
 43. A method for encapsulatingan integrated circuit die, comprising the steps of: providing a moldhaving a molding chamber and a mold gate providing a conduit forintroducing a molding compound into the chamber; providing a diecomprising a first surface, a second surface, and sides; the firstsurface with electrical elements and a plurality of bond pads formedthereon; providing a support substrate having an I-shaped openingcomprising a main elongate segment and a pair of shorter elongatesegments positioned perpendicular to and on opposing ends of the mainsegment; a hole through the support substrate on opposite ends of andadjacent to the shorter elongate segments of the I-shaped opening; aplurality of bond pad fingers formed on a side of the substrate adjacentto the opening, and a plurality of ball pads formed on the substrateadjacent to the bond pad fingers; mounting the die onto the supportsubstrate to align the bond pads within the I-shaped opening of thesupport substrate such that the holes through the support substrate areuncovered, and a gap is provided along a peripheral edge of the die andan edge of at least one of the shorter elongate segments of the openingof the support substrate; electrically connecting the bond pads throughthe opening to the bond pad fingers on the support substrate; providinga mold having a molding chamber and a mold gate providing a conduit forintroducing a molding compound into the chamber; placing the mounted diein the mold with the mold gate oriented perpendicular to the opening inthe support substrate; and introducing a molding compound through themold gate to flow the molding compound into the opening of the substrateto enclose the bond pad fingers and the electrical elements of the die,and through the gap and the hole in the substrate onto the sides of thedie.
 44. A method for encapsulating an integrated circuit die,comprising the steps of: providing a mold having a molding chamber and amold gate providing a conduit for introducing a molding compound intothe chamber; providing a die unit having a die comprising a firstsurface, a second surface, and sides, the first surface with electricalelements and a plurality of bond pads formed thereon; the first surfaceof the die mounted onto a support substrate with the bond pads exposedthrough an opening of the support substrate; placing the die unit in themold with the mold gate oriented perpendicular to the opening in thesupport substrate; and introducing a molding compound through the moldgate whereby the molding compound flows in a downward direction into theopening in the substrate to enclose the electrical elements and bondpads on the die.
 45. A method for encapsulating an integrated circuitdie, comprising the steps of: providing a mold having a molding chamberand a mold gate providing a conduit for introducing a molding compoundinto the chamber; providing a die unit comprising a die having a firstsurface, a second surface, and sides, the first surface of the die withelectrical elements and a plurality of bond pads formed thereon, and thefirst surface of the die mounted onto a support substrate with the bondpads exposed through an opening of the support substrate; placing thedie unit in the mold with the mold gate oriented perpendicular toopening in the support substrate; and introducing a molding compoundthrough the mold gate whereby the molding compound flows in an upwarddirection into the opening in the substrate to enclose the electricalelements and bond pads on the die.
 46. A method for encapsulating anintegrated circuit die, comprising the steps of: providing a mold havinga molding chamber and a mold gate providing a conduit for introducing amolding compound into the chamber; providing a die unit comprising a diehaving a first surface, a second surface, and sides, the first surfacewith electrical elements and a plurality of bond pads disposed thereon;the first surface of the die mounted onto a support substrate with thebond pads exposed through an opening of the support substrate; placingthe die unit in the mold with the mold gate oriented perpendicular tothe opening in the support substrate and positioned at about the centerof the opening; and introducing a molding compound through the mold gateto flow the molding compound into the opening of the support substrateat or about the center of the opening and toward each end of the openingto enclose the electrical elements and bond pads on the die.
 47. Amethod for encapsulating an integrated circuit die, comprising the stepsof: providing a mold having a molding chamber and a mold gate providinga conduit for introducing a molding compound into the chamber; providinga die unit comprising a die having a first surface, a second surface,and sides; the first surface of the die with electrical elements and aplurality of bond pads formed thereon; the first surface of the diemounted onto a support substrate with the bond pads exposed through anopening of the support substrate; placing the die unit in the mold withthe mold gate oriented perpendicular to the opening in the supportsubstrate and positioned at one end of the opening; and introducing amolding compound through the mold gate to flow the molding compound intothe opening in the substrate and from one end of the opening to theother end to enclose the electrical elements and bond pads on the die.48. A mold for fabricating a semiconductor die package, comprising: apair of molding plates, a chamber, and a mold gate providing a conduitfor introducing a molding compound into the chamber; the mold gateprovided in one of the molding plates and oriented in the molding plateto deliver a molding compound into the chamber perpendicularly into awire bond slot of a die unit positioned within the chamber.
 49. A moldfor fabricating a die semiconductor package, comprising: a moldcomprising first and second molding plates, a chamber, and a mold gatethrough the first molding plate providing a conduit for introducing amolding compound into the chamber; the mold gate oriented perpendicularto the second molding plate to deliver a molding compound into thechamber perpendicularly into a wire bond slot of a die unit positionedwithin the chamber between the molding plates.
 50. A mold forencapsulating a semiconductor die, comprising: first and second moldingplates, a chamber, and a mold gate providing a conduit for introducing amolding compound into the chamber; a die unit comprising a die having afirst surface, a second surface, and sides; the first surface of the diewith a plurality of bond pads disposed thereon; the first surface of thedie mounted onto a support substrate with the bond pads exposed throughan opening of the support substrate; and the die unit positioned in themold with the mold gate oriented perpendicular to the opening in thesupport substrate.
 51. The mold of claim 50, wherein the die and moldgate are oriented to allow a molding compound introduced through themold gate to flow into the opening on the support substrate in adownward direction.
 52. The mold of claim 50, wherein the die and moldgate are oriented to allow a molding compound introduced through themold gate to flow into the opening on the support substrate in an upwarddirection.
 53. The mold of claim 50, wherein the mold gate is positionedin the mold to dispense a molding compound into one end of the openingof the support substrate.
 54. The mold of claim 50, wherein the moldgate is positioned in the mold to dispense a molding compound into aboutthe center of the opening of the support substrate.
 55. The mold ofclaim 50, wherein the die unit comprises a gap between a peripheral edgeof the die and the opening of the support substrate for passage of amolding compound therethrough.
 56. The mold of claim 50, wherein the dieunit further comprises a hole in the support substrate adjacent theopening, and the hole provides a passage for a molding compoundtherethrough.
 57. The mold of claim 50, wherein the die unit comprises agap between a peripheral edge of the die and the opening of the supportsubstrate; and the support substrate further comprises a hole adjacentthe opening, and the gap and the hole provide a passage for a moldingcompound therethrough.
 58. The mold of claim 50, wherein the mold isstructured to allow flowing of the molding compound onto the secondsurface of the die.
 59. The mold of claim 58, wherein the mold isfurther structured to prevent flowing of the molding compound onto thesecond surface of the die.
 60. A mold for encapsulating a semiconductordie, comprising: first and second molding plates, a chamber, and a moldgate providing a conduit for introducing a molding compound into thechamber; a die unit comprising a die having a first surface, a secondsurface, and sides; the first surface of the die with a plurality ofbond pads thereon; the first surface of the die mounted onto a supportsubstrate with the bond pads exposed through an opening of the supportsubstrate; and the die unit positioned in the mold with the mold gateoriented perpendicular to the opening in the support substrate, and thedie and mold gate oriented to allow a molding compound introducedthrough the mold gate to flow into the opening in the support substratein a downward direction.
 61. A mold for encapsulating a semiconductordie, comprising: first and second molding plates, a chamber, and a moldgate providing a conduit for introducing a molding compound into thechamber; a die unit comprising a die having a first surface, a secondsurface, and sides; the first surface of the die with a plurality ofbond pads disposed thereon, the first surface of the die mounted onto asupport substrate with the bond pads exposed through an opening of thesupport substrate; and the die unit positioned in the mold with the moldgate oriented perpendicular to the opening in the support substrate andthe die and mold gate oriented to allow a molding compound introducedthrough the mold gate to flow directly onto the first surface of the diein an upward direction.
 62. A mold for encapsulating a semiconductordie, comprising: first and second molding plates, a chamber, and a moldgate providing a conduit for introducing a molding compound into thechamber; a die unit comprising a die having a first surface, a secondsurface, and sides; the first surface of the die with a plurality ofbond pads disposed thereon; the first surface of the die mounted onto asupport substrate with the bond pads exposed through an opening of thesupport substrate; and the die unit positioned in the mold with the moldgate oriented perpendicular to the opening in the support substrate, andpositioned on the mold to dispense a molding compound directly into oneend of the opening.
 63. A mold for encapsulating a semiconductor die,comprising: first and second molding plates, a chamber, and a mold gateproviding a conduit for introducing a molding compound into the chamber;a die unit comprising a die having a first surface, a second surface,and sides; the first surface of the die with a plurality of bond padsdisposed thereon; the first surface of the die mounted onto a supportsubstrate with the bond pads exposed through an opening of the supportsubstrate; and the die unit positioned in the mold with the mold gateoriented perpendicular to the opening in the support substrate, andpositioned on the mold to dispense a molding compound into about thecenter of the opening.
 64. A semiconductor assembly, comprising: asemiconductor die having a first surface, a second surface, and sides;the first surface having a plurality of bond pads disposed thereon in anI-shaped layout; and a support substrate having a first side, a secondside, and an I-shaped opening corresponding to the layout of the bondpads, a plurality of bond pad fingers disposed on the first side of thesupport substrate and adjacent to the opening; the first surface of thedie mounted onto the second side of the support substrate with the bondpads exposed through the opening of the support substrate and connectedto the bond pad fingers.
 65. The semiconductor assembly of claim 64,further comprising an adhesive layer interposed between the die and thesupport substrate.
 66. The semiconductor assembly of claim 65, whereinthe adhesive layer comprises an I-shaped opening corresponding to theopening of the support substrate.
 67. The semiconductor assembly ofclaim 65, wherein the adhesive layer comprises a pair of adhesive stripspositioned on opposite sides and adjacent to the I-shaped opening. 68.The semiconductor assembly of claim 64, further comprising a gap betweena peripheral edge of the die and the opening of the support substrate.69. The semiconductor assembly of claim 64, further comprising a holeadjacent the opening of the support substrate, the hole providing apassage through the support substrate.
 70. The semiconductor assembly ofclaim 64, further comprising a gap between a peripheral edge of the dieand the opening of the support substrate, and a hole adjacent theopening of the support substrate, the hole providing a passage throughthe support substrate.
 71. The semiconductor assembly of claim 64,further comprising a plurality of solder balls mounted on ball padsadjacent to the bond pad fingers.
 72. The semiconductor assembly ofclaim 64, wherein the sides of the die are covered by the moldingcompound, and the second surface of the die is uncovered.
 73. Thesemiconductor assembly of claim 64, wherein the sides and the secondsurface of the die are covered by the molding compound.
 74. Thesemiconductor assembly of claim 64, further comprising a moldingcompound filling the opening and covering the bond pads.
 75. Thesemiconductor assembly of claim 64, further comprising a heat sinkattached to a portion of the first surface of the die.
 76. Asemiconductor package, comprising: a semiconductor die mounted on asupport substrate; the die having a first surface, a second surface, andsides, and a plurality of bond pads mounted in an I-shaped layout on thefirst surface of the die; the support substrate having a first side, asecond side, an I-shaped opening, a plurality of bond pad fingersmounted on the first side of the support substrate and adjacent to theopening; the first surface of the die mounted onto the second side ofthe support substrate with the bond pads exposed through the opening ofthe support substrate and connected to the bond pad fingers; and thebond pads on the die covered by a molding compound.
 77. Thesemiconductor package of claim 76, wherein the sides of the die arecovered by the molding compound, and the second surface of the die isuncovered.
 78. The semiconductor package of claim 76, wherein the sidesand the second surface of the die are covered by the molding compound.79. The semiconductor package of claim 76, further comprising a gapbetween a peripheral edge of the die and the opening of the supportsubstrate.
 80. The semiconductor package of claim 76, further comprisinga hole adjacent the opening of the support substrate, the hole providinga passage through the support substrate.
 81. The semiconductor packageof claim 76, further comprising a gap between a peripheral edge of thedie and the opening of the support substrate, and a hole adjacent theopening of the support substrate, the hole providing a passage throughthe support substrate.
 82. A semiconductor package, comprising: asemiconductor die mounted on a support substrate; the die having a firstsurface, a second surface, and sides, and a plurality of bond padsmounted in an I-shaped layout on the first surface of the die; thesupport substrate having a first side, a second side, an I-shapedopening, a plurality of bond pad fingers mounted on the first side ofthe support substrate and adjacent to the opening; the first surface ofthe die mounted onto the second side of the support substrate with thebond pads exposed through the opening of the support substrate andconnected to the bond pad fingers; and the bond pads and the sides ofthe die are covered by the molding compound, and the second surface ofthe die is uncovered.
 83. A semiconductor package, comprising: asemiconductor die mounted on a support substrate; the die having a firstsurface, a second surface, and sides, and a plurality of bond padsmounted in an I-shaped layout on the first surface of the die; thesupport substrate having a first side, a second side, an I-shapedopening, a plurality of bond pad fingers mounted on the first side ofthe support substrate and adjacent to the opening; the first surface ofthe die mounted onto the second side of the support substrate with thebond pads exposed through the opening of the support substrate andconnected to the bond pad fingers; and the bond pads, the sides and thesecond surface of the die are covered by the molding compound.
 84. Asemiconductor package, comprising: a semiconductor die mounted on asupport substrate; the die having a first surface, a second surface, andsides, and a plurality of bond pads mounted in an I-shaped layout on thefirst surface of the die; the support substrate having a first side, asecond side, an I-shaped opening, a plurality of bond pad fingersmounted on the first side of the support substrate and adjacent to theopening; the first surface of the die mounted onto the second side ofthe support substrate with the bond pads exposed through the opening ofthe support substrate and connected to the bond pad fingers, and a gapbetween a peripheral edge of the die and the opening of the supportsubstrate; and the bond pads on the die covered by a molding compound.85. A semiconductor package, comprising: a semiconductor die mounted ona support substrate; the die having a first surface, a second surface,and sides, and a plurality of bond pads mounted in an I-shaped layout onthe first surface of the die; the support substrate having a first side,a second side, an I-shaped opening, a hole adjacent the opening throughthe substrate, and a plurality of bond pad fingers mounted on the firstside of the support substrate and adjacent to the opening; the firstsurface of the die mounted onto the second side of the support substratewith the bond pads exposed through the opening of the support substrateand connected to the bond pad fingers, and the hole providing a passagethrough the support substrate; and the bond pads on the die covered by amolding compound.
 86. A semiconductor package, comprising: asemiconductor die mounted on a support substrate; the die having a firstsurface, a second surface, and sides, and a plurality of bond padsmounted in an I-shaped layout on the first surface of the die; thesupport substrate having a first side, a second side, an I-shapedopening, a hole adjacent the opening through the substrate, and aplurality of bond pad fingers mounted on the first side of the supportsubstrate and adjacent to the opening; the first surface of the diemounted onto the second side of the support substrate with the bond padsexposed through the opening of the support substrate and connected tothe bond pad fingers, the hole providing a passage through the supportsubstrate; and a gap between a peripheral edge of the die and theopening of the support substrate; and the bond pads on the die coveredby a molding compound.